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HAST.CONF(5) FreeBSD File Formats Manual HAST.CONF(5)
NAMEhast.conf -- configuration file for the hastd(8) deamon and the
hastctl(8) utility.
DESCRIPTION
The hast.conf file is used by both hastd(8) daemon and hastctl(8) control
utility. Configuration file is designed in a way that exactly the same
file can be (and should be) used on both HAST nodes. Every line starting
with # is treated as comment and ignored.
CONFIGURATION FILE SYNTAX
General syntax of the hast.conf file is following:
# Global section
control <addr>
listen <addr>
replication <mode>
timeout <seconds>
on <node> {
# Node section
control <addr>
listen <addr>
}
on <node> {
# Node section
control <addr>
listen <addr>
}
resource <name> {
# Resource section
replication <mode>
name <name>
local <path>
timeout <seconds>
on <node> {
# Resource-node section
name <name>
# Required
local <path>
# Required
remote <addr>
}
on <node> {
# Resource-node section
name <name>
# Required
local <path>
# Required
remote <addr>
}
}
Most of the various available configuration parameters are optional. If
parameter is not defined in the particular section, it will be inherited
from the parent section. For example, if the listen parameter is not
defined in the node section, it will be inherited from the global sec-
tion. In case the global section does not define the listen parameter at
all, the default value will be used.
CONFIGURATION FILE DESCRIPTION
The <node> argument can be replaced either by a full hostname as obtained
by gethostname(3), only first part of the hostname, or by node's UUID as
found in the kern.hostuuidsysctl(8) variable.
The following statements are available:
control <addr>
Address for communication with hastctl(8). Each of the following
examples defines the same control address:
uds:///var/run/hastctl
unix:///var/run/hastctl
/var/run/hastctl
The default value is uds:///var/run/hastctl.
listen <addr>
Address to listen on in form of:
protocol://protocol-specific-address
Each of the following examples defines the same listen address:
0.0.0.0
0.0.0.0:8457
tcp://0.0.0.0
tcp://0.0.0.0:8457
tcp4://0.0.0.0
tcp4://0.0.0.0:8457
The default value is tcp4://0.0.0.0:8457.
replication <mode>
Replication mode should be one of the following:
memsync
Report the write operation as completed when local write com-
pletes and when the remote node acknowledges the data
receipt, but before it actually stores the data. The data on
remote node will be stored directly after sending acknowl-
edgement. This mode is intended to reduce latency, but still
provides a very good reliability. The only situation where
some small amount of data could be lost is when the data is
stored on primary node and sent to the secondary. Secondary
node then acknowledges data receipt and primary reports suc-
cess to an application. However, it may happen that the sec-
onderay goes down before the received data is really stored
locally. Before secondary node returns, primary node dies
entirely. When the secondary node comes back to life it
becomes the new primary. Unfortunately some small amount of
data which was confirmed to be stored to the application was
lost. The risk of such a situation is very small, which is
the reason for this mode to be the default.
fullsync
Mark the write operation as completed when local as well as
remote write completes. This is the safest and the slowest
replication mode. The fullsync replication mode is currently
not implemented.
async
The write operation is reported as complete right after the
local write completes. This is the fastest and the most dan-
gerous replication mode. This mode should be used when
replicating to a distant node where latency is too high for
other modes. The async replication mode is currently not
implemented.
timeout <seconds>
Connection timeout in seconds. The default value is 5.
name <name>
GEOM provider name that will appear as /dev/hast/_name_. If name
is not defined, resource name will be used as provider name.
local <path>
Path to the local component which will be used as backend provider
for the resource. This can be either GEOM provider or regular
file.
remote <addr>
Address of the remote hastd daemon. Format is the same as for the
listen statement. When operating as a primary node this address
will be used to connect to the secondary node. When operating as a
secondary node only connections from this address will be accepted.
EXAMPLES
The example configuration file can look as follows:
resource shared {
local /dev/da0
on hasta {
remote tcp4://10.0.0.2
}
on hastb {
remote tcp4://10.0.0.1
}
}
resource tank {
on hasta {
local /dev/mirror/tanka
remote tcp4://10.0.0.2
}
on hastb {
local /dev/mirror/tankb
remote tcp4://10.0.0.1
}
}
FILES
/etc/hast.conf The default hast.conf configuration file.
/var/run/hastctl Control socket used by the hastctl(8) control utility
to communicate with the hastd(8) daemon.
SEE ALSOgethostname(3), geom(4), hastctl(8), hastd(8).
AUTHORS
The hast.conf was written by Pawel Jakub Dawidek <pjd@FreeBSD.org> under
sponsorship of the FreeBSD Foundation.
FreeBSD 10.1 February 1, 2010 FreeBSD 10.1